Adding-machine.



No. 769,892. PATENTBD SEPT. 13, 1904. s. H. DBYSDALE.

ADDING MAGHINEQ APPLICATION FILED Km. 29. 1904. no MODEL 3 SHEETS-SHEET 1 Witnesses ventor.

r I l. Htkomegs PATENTED SEPT. 13, 1904.

S. H. DRYSDALE. ADDING MACHINE.

APPLICATION FILED 1113.29, 1904.

3 SHEBTSBHEET 2 an: I '5? w fimr.

b w y No. 769,892. PATENTED SEPT. 13, 1904. S; H. DRYSDALE.

ADDING MACHINE.

APPLICATION FILED 1413.29, 1904.

N0 MODEL. 3 SHEETS-SHEET 3.

. Witnesses I Z e I Inventor. gm l 9 Httomegs Adding-Machine, of which the UNITED STATES Patented September 13, 1904.

PATENT OFFICE.

-ADDlNG-MACH|NE.

SPECIFICATION forming part of Letters Patent No. 769,892, dated September 13, 1904. Application filed March 29, 1904. Serial No. 200,574. (No model.)

To all whom, it may concern Be it known that I, STEPHEN H. DRYSDALE, a citizen of the United States, residing at Versailles, in the county of Morgan and State of Missouri, have invented a new and useful following is a specification.

This invention relates to improvements in addingmachines.

The principal object of the invention is to provide a novel form of adding-machine in which numerals are arranged in a helical column extending around a cylinder that receives step-by-step rotative movement from fingerkeys and to employ in connection therewith a pointer that is moved in a direction lengthwise of the cylinder in order to follow the helical column.

A further object of the invention is to provide a machine of this type having a novel means for checking the movement of the cylinder at the completion of each stroke of a finger-key in order to prevent the cylinder from movement past a predetermined point from its own momentum.

A still further object of the invention is to provide a device of this character in which the parts may be quickly adjusted to Zero position in readiness to start different calculations.

l/Vith these and other objects in view, as will more fully hereinafter appear, the invention consist in the novel construction and arrangement of parts hereinafter fully clescribed, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportions, size, and minor details of the structure may be made without departing from the spirit or sacrificing any of the advantages of the invention.

In the accompanying drawings, Figure 1 is a front elevation of an adding-machine constructed in accordance with the invention, the front of the casing being removed. Fig. 2 is a plan view of the same. Fig. 3 is a transverse sectional view of the machine on'the line 3 3 of Fig. 1. Fig. 4: is a similar view on the line 1 4; of Fig. 1. Fig. 5 is a detail perspective view illustrating the mounting of one of the key-levers.

Similar numerals of reference are employed to indicate corresponding parts throughout the several figures of the drawings.

The working parts of the machine are supported on a suitable framework 1, having bearings'ffor the reception of a shaft 2, to which is secured a cylinder 3. On the cylinder is arranged a helical column of numerals, the column being divided into spaces by longitudinally-disposed parallel lines arranged at equidistant intervals throughout the circumference of the cylinder, and in each one of the spaces so formed is placed a numeral or numerals, starting at the left hand of the cylinder with Zero and thence continuing in consecutive order for the full capacity of said cylinder.

To the shaft 2 at the end of the cylinder is secured a ratchet-wheel 4, having teeth of a number equal to the number of parallel spaces into which the circumference of the cylinder is divided, and with this ratchetwheel engages a spring-pressed pawl 5, that prevents retrograde movement of the cylinder and ratchet-wheel. Pivotally mounted on the shaft is a pawl-carrying arm 6, having at its outer end a spring-pressed pawl 7 in engagement with the teeth of the ratchetwheel and serving as a means for imparting a step-by-step rotative movement to the cylinder, the movement being proportioned to the value represented by the finger-key depressed. The pawl-carrying arm 6 is connected to one end of a torsion-spring 8, that encircles the shaft, and has its opposite end secured to the fixed frame.

At a point under the cylinder are arranged a number of key-levers 10, having fingerpieces or buttons on which are marked theseveral numerals from 1 to 9, inclusive, and these are all pivotally mounted on a common fulcrum-rod 11, springs 12 being employed to restore the levers to elevated position after each operation. At one side of the frame is pivoted a lever 12, that is disposed under the several key-levers and is arranged at an angle with respect thereto, said lever being connected bya rod 1a to the pawlcarrying lever 6 and its upward movement being limited by a stop 15. The key-levers when depressed impart movement to the lever 12', and consequently to the cylinder, to an extent proportioned to the values represented by the numerals which theybear, and in order that the extent of operating movement of the key-levers may be substantially the same Without regard to their different values the key-levers bearing the lower numbers, such as 1, 2, 3, are arched in order that there may be some considerable lost motion on the depressing movement of the keys before the levers actually strike the operatinglever 12', while the levers of higher denominations will have considerably less lost motion and being disposed nearest the fulcrum-point of the lever 12 will effect a correspondingly greater movement of the free end of the lever.

At the top of the frame and supported by standards 17 which form a part thereof, is a rod 18, that is arranged parallel with the main shaft 2, and on this rod is pivotally mounted a bar 19, having teeth 20 on its under side, which are to be engaged by a worm 21 on the end of the cylinder 3, the worm being in the form of a single helical tooth which follows the pitch of the helical column of figures. This bar is provided withahandle 22, so that by depressing the handle the bar may be conveniently raised and the rack disengaged from the worm in order to permit adjustment of the bar. The bar carries a pointer 23, which follows the column of figures, the bar moving lengthwise of the cylinder as the latter rotates. In restoring the parts to initial position the bar 19 is elevated until the rackteeth are disengaged from the worm, and then the bar is slid on the rod to the left until the pointer is at its initial position, movement being stopped when the bar strikes against the standard 17 at the left of the machine.

At one end of the cylinder is a projecting pin 25, so positioned with respect to the zeromark that when a small locking-lever 26, that is pivoted to the frame, is moved against the end of the cylinder it will be engaged by the pin and movement of the cylinder will cease with the zero-mark in proper position before the commencement of a calculation. The turning of the cylinder may be facilitated by means of a small milled knob 27.

Extending from the end of the cylinder is an annular row of pins 28, disposedcone in alinement with each horizontal column on the periphery of the cylinder, and with these pins engages a stop-lever 30, carried by a pivotallymounted bar 31, that is supported by the frame, the spring 32, which presses against the bar, serving normally to hold the lever out of engagement with the pins. Each of the key-levers is provided with a projecting finger 33,

which is adapted to engage the bar 31 at or near the completion of the downstroke of the keylever, so that as the movement of the cylinder is completed the lever 30 will be forced into engagement with one of the teeth at the end of the cylinder and will thus lock the cylinder from further movement and prevent errors in calculation due to excess travel of the cylinder under its own momentum.

In using the machine, the parts being adjusted to zero position, each column of figures is added separately, starting at the righthand column, and then after one column is added the machine is adjusted to zero position and a second column is added together with the remainder from the first column, and in this way any number of columns may be consecutively added and the process of addition accomplished without any mental strain on the part of the operator.

Having thus described the invention, is claimed is 1. In an adding-machine, a cylinder having a helical column of numerals arranged in successive order, a worm secured to the end of the cylinder and revoluble therewith, the pitch of the worm being equal to the pitch of the helical column, a rack-bar with which the worm engages, a pointer carried by the rackbar and following the helical column of numerals, finger-keys for imparting step-bystep rotative movement to the cylinder, said rack being movable to permit its engagement with and disengagement from the worm.

2. The combination in an adding-machine, of a cylinder having a helical column of numerals, a worm secured to and revoluble with the cylinder, said worm having a pitch' equal to that of the helical column of numerals, a pivotally-mounted rack movable into engagement with and disengagement from the worm, a pointer carried by the rack and following the numerals, and a handle or knob secured to the rack and serving as a means for restoring the same to zero position.

3. The combination in an adding-machine, of a revoluble cylinder, a worm secured to one end of the cylinder, a helical column of figures arranged on the cylinder, the helix being of a pitch equal to that of the worm, a rack with which the worm engages, a support on which said rack is free to slide, a pointer carried by the rack, means for imparting step-by-step rotative movement to the what cylinder, and means for automatically looking the cylinder at the end of each step-bystep movement. v

In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two witnesses.

STEPHEN H. DRYSDALE. Witnesses:

JAooB S. EARNEST, JOHN T. BEALE. 

